Fix Cloud Run action example using service-account-based auth

[RobotHanzo]

Added missing token_format: 'access_token' for the google-github-actions/auth@v0 step, fixing Cloud Run action example using service-account-based auth, ensuring docker-auth works

[google-cla]

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[RobotHanzo]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

signed